The present invention relates to a floating caliper spot-type disc brakes in general, and more particularly to disc brakes of this type which are suited for use in automotive vehicles.
There are already known various constructions of disc brakes of this type which are being used for applying braking forces to a disc which is rotatably mounted on a support, such as on the body of a motor vehicle. One construction of a disc brake of this type is disclosed in the commonly owned U.S. Pat. No. 4,219,106 which shows that the disc brake includes a carrier member which is stationarily mounted on the vehicle, and a caliper member which is floatingly guided on the carrier member for translatory movement in and opposite to a predetermined direction in response to the energization and de-energization of the brake. The floating guidance of the caliper member on the carrier member is at least partially accomplished, in this particular construction, by two guide pins rigidly connected to the carrier member which coaxially pass through associated openings in the caliper member. In another floating caliper spot-type disc brake of the type here under consideration which is disclosed in the commonly owned U.S. Pat. No. 4,276,965, the guide pins are supported and guided in the openings of the carrier member by respective sleeves of elastic material which are interposed between the external surfaces of the respective pins and the surfaces bounding the openings in the carrier member.
Among other advantages, the mounting of the guide pins in the associated openings via the elastic sleeves avoids the generation of rattling noises at this mounting region. However, it was found that, especially when the vehicle travels over rough roads, the oscillatory movements of the caliper member and/or other components of the brake which are or may come into contact with the carrier or caliper members may still result in the generation of rattling noises, especially at the brake region which is remote from the mounting region. Thus, it is customary in the brake manufacturing field to employ a resilient element or a plurality of resilient elements for eliminating any clearances which may exist between the various brake components and the presence of which could result in the generation of rattling noises.
In this construction, the caliper member rests on portions of the backing plate of a brake shoe which is disposed at the aforementioned remote region. The backing plate, in turn, is being guided on arms of the carrier member which extend over the periphery of the brake disc. The caliper member is guided on the two bolts or pins for sliding axially thereof. The pins are secured to the carrier member and are disposed at the part of the caliper member which carries the actuating cylinder, extending in the direction of the axis of the cylinder. To achieve the elimination of any clearances and thus of the rattling noises, there is provided a leaf-spring which is fastened at its central section to the end face of the caliper member which is remote from the actuating device and which includes two spring arms that extend substantially parallel to the brake disc and are in sliding contact with the arms of the carrier member. Despite the fact that the construction and mounting of this spring are much simpler than those encountered in connection with previously proposed biasing or urging springs provided for a similar purpose, the fact remains that the very need for providing and mounting an additional biasing element complicates the construction of the disc brake and makes the assembly thereof more time-consuming than necessary. Moreover, the manufacturing costs of the spring have to be added to those of the remainder of the disc brake, together with the labor costs attendant to the mounting of the spring, which further contributes to the already relatively high cost of the disc brake.